Fusible busway plug



Nov.,21, 1967 L. c. GOODRIDGE FUSIBLE BuswAY PLUG 3 Sheets-Sheet 1 Filed May 5, 1966 m. w w 0 S l A T7 ORA/E Y Nov. 2 1, 1967 c. GOODRIDGE 3,354,352

FUS IBLE BUSWAY PLUG Filed May 5, 1966 3 Sheets-Sheet 2 .5 MW mm a V6 WC m a w W A A7 7' Tom/5 v 1957 L. c. GOODRIDGE FUSIBLE BUS'NAY PLUG Filed May 5, 1966 5 Sheets-Sheet 3 lA/VENTOR. [A wa /vac C 6000/2/06: HM?- y United States Patent 3,354,352 FUSIBLE BUSWAY PLUG C. Goodridge, Bristol, Conn., Electric Company,

assignor to a corporation of New ABSTRACT OF THE DISCLOSURE A fusible power take-off plug for bus bar type distribution systems is provided of the type including a metallic box or enclosure having a back wall with contact stabs projecting therefrom and arranged to be mounted on a busway with the back wall against the busway and the contact stabs in contact with the bus bars; a control switch is mounted on a side wall of the plug for ready dissipation of heat therefrom, and fuse receiving sockets are located adjacent the top wall. The space within the enclosure adjacent the switch and below the fuses constitutes a wiring space.

Background of the invention 1. Field of the invenlion.The present invention relates to plug-in type power take-off devices for use with bus bar type electric power distribution systems, and more particularly to such devices which include a switching device and fuses in series therewith.

Description of the prior art conducting and radiating materials, etc. Such measures,

however, have added substantially to the cost of the devices, and in addition, make the wiring and use thereof more difficult.

In addition to the above, prior art plug-in type power take-oft devices have occupied a substantial amount of space lengthwise of the busway on which they are used. This limits the number of such devices which can be positioned within a given length of busway, sometimes leading to inconvenience and requiring location of one or more devices more remote from the point of power utilization than desired.

Summary of the invention It is an object of my invention to provide a new and improved switch-and-fuse type of busway plug having greater heat dissipation ability than comparable prior art 7 devices.

Another object of the invention is to provide a new and improved switch-and-fuse busway plug which will permit the utilization of an increased number of such plugs in a finite length of busway.

It is another object of the invention to provide a busway plug of the type described which is substantially smaller than prior art devices of comparable capacity, without sacrificing wiring gutter space.

In accordance with the invention, the conventional arrangement whereby the switch and fuses are mounted on the back wall of the plug enclosure, i.e., the wall from which the contact stabs project, is not used. Instead, the switch and fuses are mounted on side walls of the enclosure. This arrangement permits the heat from the switch and fuses to be readily dissipated to the surrounding air by the exposed outer surface of the side wall of the enclosure. This, of course, is not possible if the switch and fuses are mounted on the bottom wall since, in use, the wall is against the housing of the busway which not only impedes dissipation of heat, but is itself a heat'source.

In accordance with another aspect of the invention, the switch is mounted on a first side wall of the plug enclosure, and the fuses are mounted on a second side wall, extending at right angles to the first side wall. This provides a much more compact arrangement and results in a plug having much shorter over-all dimensions or length.

The invention will be more fully understood by reference to the following detailed description, taken in conjunction with the accompanying drawings, and its scope will be pointed out in the appended claims.

Description of the drawings Referring to the drawings:

FIGURE 1 is a perspective view of incorporating the present invention, shown electrical busway, shown in dotted lines;

FIGURE 2 is a side view of the fusible of FIGURE 1;

FIGURE 3 is a partially exploded perspective view of the interior of the busway plug of FIGURE 1, with parts of the enclosure broken away to show the interior;

FIGURE 4 is a side view of a portion of the operating mechanism of the busway plug of FIGURE 1, and

FIGURE 5 is a side View of a portion of the interior of the busway plug of FIGURE 1, illustrating the cover interlock mechanism of the plug;

FIGURE 6 is a partially exploded perspective view of the cover interlock of the busway plug of FIGURE 3.

Referring now to FIGURE 1, the invention is shown as incorporated in a fusible busway plug 10, shown mounted on an electrical busway 11. The plug 10 is detachably mounted on the busway 11 by means of two pairs of clamping arms 12, which engage the side flanges 13 of the busway. Each pair of arms 12, as shown in FIGURE 2, is mounted in a housing 14, that is secured to the exterior of the plug 10 by means of screws 15. Take-up screws 16, which engage the clamping arms 12, are employed to tighten the arms 12 and so secure the a busway plug mounted on an busway plug 1 plug 10 to the busway 11.

The busway plug 10, as shown in FIGURE 3, includes a bottom wall 17, four side walls 18, and a cover 19, the latter constituting the top wall of the plug 10. As shown in dotted lines in FIGURE 2, the cover 19 is hinged to one of the side walls 18. When closed, the cover 19 is held in that position by means of a spring biased hook member 20, which passes through an opening 21 in the cover; The hook member 20 is mounted on the side wall opposite that on which the cover 19 is hinged. By utilizing the opening 22 in the hook member 20, a padlock (not shown) or other suitable means may be employed to lock the cover 19 in closed position.

The side walls 18 may be fastened together by means of screws 74, as shown for example in FIGURES 1 and 3. Such a mode of construction is advantageous since it facilitates the assembly of the operating mechanism of the plug, by permitting the parts to be assembled on the side walls prior to the side walls being fastened together.

Protruding through the center portion 17a of the bottom wall 17 of the plug 10 are four plug-in stabs, there being one stab 23 for each of the three phases of the multiphase electrical busway 11, and a neutral stab 24. As seen in FIGURE 1, the plug-in stabs 23 engage the phase conducting busbars 25, while the netural stab 24 engages the neutral busbar 26. To support and provide proper alignment between the stabs 23, 24 and the respective busbars 25, 26 there is provided an insulation block 27 suitably mounted in the center portion 17a of the bottom wall 17 of the plug .10. The stabs 23, 24, which pass through openings provided in the block 27., are held thereby in spaced apart relation whereby the distance between stabs corresponds to the distance between the busbars of the busway 11. Barrier members 28 are provided with the insulation block 27 for the purpose of insulating the plug-in stabs from each other. There is also supported on the insulation block 27, a conductor strap 41 which is connected at one end of the neutral stab 24 and which has afiixed to its other end a terminal lug 42.

As shown in FIGURE 3, one of the side walls 18 of the plug 10 has an insulation member 29 secured thereto and fixedly mounted thereon are three switch mechanisms 30, one for each of the phases of the multi-phase electrical busway 11. Each of the switch mechanisms 30 is electrically connected to one of the plug-in stabs 23 by means of conductor straps such as those designated 31 and 32 in FIGURE 3. A fuse 33, shown in dotted lines in FIGURE 4, may be detachably mounted in a pair of spaced fuse clips 34, 35, whereby it is connected in series with one of the switch mechanisms 30 by conductor straps The straps 37 are sandwiched between the conductor straps 36 and the fuse clips 34, and are fixedly secured thereto. A portion of each of the straps 37 extends in juxtaposed relation to the insulation member 29 positioned on one of the side walls 18, as shown in FIGURE 3. The function of the straps 37 is to bleed off the heat generated in the fuses 3'3 and to thereby cause this heat to be transmitted to the sidewall 18 and therethrough to the outside of the plug enclosure.

The straps 38 are mounted on an insulation member 39, and have affixed thereto terminal lugs 40. The straps 3'8 and lugs 40 are mounted so as to be readily interchangeable with other straps and lugs, which may be required when it is desired to employ fuses having different electrical ratings, requiring different size 'lugs 40 and difierent capacity straps 3'8. p I

At-pair of rails 43, only one of which is shown in FIG- URE 3, are secured to opposing side walls 18of the plug 10. The insulation member '39 is fastened, to these rails by means of screws 44, or other suitable fastening means. The screws 44 may be inserted into any of a series of holes 45 provided in the rails 43, thereby affording a means of varying the distance between the fuse clips 34 and 35 in order to accommodate different length fuses.. The handle portion of each of the switch mechanisms 30 is secured to a common bar 46 from which extend pins 47, thus providing, .in effect, a single 3-pole switch. The pins 47 extend into openings 48 provided in the yokemember 49. One of the arm portions 50 of the yoke 49, as "shown in FIGURE 3, is fastened by means of screws 52 to one end of alever member 51, the other end of which is'connected to rectilin arly-moving or slide type actuating member 54 by means of 'a stud 53 carried thereby. One of the rails 43 is provided with a slotted portion 55 to accommodate the sliding movement of the member 51 which is positioned between the rail 43 and the plugsi'de wall 1'8.-

Referring now to FIGURES 3,, and 6 the actuating member .54, which is horizontally movable along side wall 18 on studs 56, has elongated portions 54a and 54b which cooperate with interlock member 57 and cover interlock 58, respectively, in a manner that will be more fully described later. Interlock member 57 is slidably supported .on side wall 18 by rivets 59 and has an arm 57a formed integrally therewith. Interlock member .57 is spring-biased to its upper position by spring 60 extending between the member 57 and an opening in wall 18. Cover interlock 58 comprises a U-shaped bracket 58d having a slot 58e therein, an L-shaped member 58 havinga hook portion 58c .at one end which .is movable in the slot 589 provided in the bracket 58d and a raised portion 584 at the other end thereof, and a spring 58g having one end fixed to the bracket 58d and the other end to the L-shaped member 58 When the cover interlock 58 is secured to the inner surface of the cover 19, the L-shaped member 58 is captured between the U-shaped bracket 58d and the cover 19. However, the L-shaped member 58 pin '62 may be moved against the bias of spring 58g by employment of an appropriate tool inserted into the opening 58b which is provided in the raised portion 58a.

The pin 62 provided on the member 54 moves in slot 63 provided in fan-shaped member 64. The member 64 is secured to the interior of the cover 19 by means of screws 65 which extend into a bearing 66 mounted on the fan-shaped member 64. The screws 65 also serve to movably mount a handle 67 on the exterior of the cover 19. As best seen in FIGURE 1, there is also mounted on the exterior of cover 19, a padlock-receiving bracket 68 which has the same configuration as the upstanding portion 671': of the handle 67, and which is positioned such that it limits the extent of movement of the handle 67.

Another handle 69 is mounted on a side wall 18 of the plug 10 by means of the screws 52 which, as previously described, also serve to interconnect one of the arm portions 50 of the yoke 49 to the lever member 51. The side wall 18 has an opening or openings, not shown, permitting the passage of the screws 52, and the handle 69 has suitable bearing surfaces, not shown, which cooperate with the side wall 18. Associated with the handle 69 is a padlock-receiving bracket member 70 which performs a function similar to that of the padlock member 68 associated with handle67. Either of these two handles 67 or 69, depending on which is the most accessible when the fusible busway plug 10 is mounted on the busway 11, may be employed to operate the switch mechanisms 30.

In describing the operation of the mechanisms of the plug 10, particular reference is made to FIGURE 1 wherein both handles 67 and 69 are shown in the OFF position, and FIGURE 3 wherein the side slide member '54, arm portion 50 and the member 51 movable therewith are shown in the position which they occupy when the switch mechanisms 30 are in the OFF position. As noted previously, either handle 67 or 69 may be employed to move the switch mechanisms 30 to their ON position, but because of the interlock arrangement built into the plug '10, the handle 67 and '69 will be operative for this purpose only when the cover 19 is closed. This is because of the fact that unless the cover 19 is closed,

carried by side slide member 54 cannot be positioned in the slot 63 of fan-shaped member 64. Thus any movement of the handle 67 will not be transmitted to the side slidemember 54, and thereby through member 51, and arm 50 of theyoke 49 to pins 47 carried by bar 46, the movement of which controls the movement of the switch mechanisms 30 between their ON and OFF" positions.

Also, with the cover 19 opened, it is not possible to move the handle 69 from the OFF to the ON position shown in phantom lines in FIGURE 1, because any such movement will be imparted to slide 51 and thereby to side slide member 54. However, when the cover 19 is opened, the interlock member 57 under the bias of spring 60 is in its uppermost position thereby blocking any substantial horizontal movement of side slide member 54, and thus not allowing the handle 69 to move to 67 is rotated from the OFF to the ON position, this rotational movement is imparted to the member 64, and results in the side slide member 54 being moved horizontally, thereby causing the switch mechanisms 30 to move from their OFF to their ON positions.

It should be further noted here that the fan-shaped member 64 will prevent the cover 19 from being closed unless pin 62 is aligned in slot 63. This is because padlock member 68, which was described earlier, limits the extent to which handle 67 and member 64 fixedly mounted thereto can be moved. Accordingly, in any position to which the fan-shaped member 64 is free to move, other than that in which pin 62 and slot 63 are aligned, the pin 62 will engage the bottom side of the members 64 thereby preventing the cover 19 from completely closng.

As noted earlier, the plug 10 is provided with a cover interlock 58, which normally prevents the cover from being opened when the switch mechanisms 30 are in the ON position. This is because as the side slide member 54 moves horizontally to the position shown in FIG- URE 5, portion 54b thereof slides over the hook portion 580 of the cover interlock 58 thereby preventing the cover from being raised. This cover interlock may be defeated, however, by inserting an appropriate tool into the opening 581; of the interlock 8 and thereby rotating the hook portion 58c out from under the portion 54b.

The area below the fuses 33 and between the terminal lugs 40 and the bottom wall 17 constitutes the wiring space or gutter for the plug 10. The length of this wiring gutter may be increased, if required, merely by increasing the depth of the plug, thereby permitting the same number of plugs to be utilized in any given length of busway since the length of the plug and not the depth thereof determines the number of plugs which can be utilized.

The wiring which is used to connect the power consuming apparatus or load to the terminal lugs 40 and 42 is inserted into the interior of the plug through either of tWo openings 71 (only one shown) provided in opposing side walls 18 of the plug. The selected one of the openings 71 which is utilized for the wiring is provided with a projecting cover 72, as seen, for example, in FIG- URES 1 and 3 having frangible portions or knockouts 73. Since terminal lugs 40 are positioned in a plane which lies above that of the openings 71, a bend must be provided in the wiring before it can be connected to the lugs 40. Normally, it would be necessary for all of this bend to be positioned within the interior of the side Walls 18 of the plug. However, by utilizing a projecting cover 72, a portion of the bend in the wiring may extend into the projecting cover, thereby providing more room within the interior of the plug, and also reducing the degree of bend required in the wiring.

The other opening 71 is covered by an ordinary metal plate (not shown). The cover 72 and the metal plate are interchangeable, thereby permitting the plug to be wired from either side.

While a specific embodiment of my invention has been shown, it will be readily appreciated that many modifications thereof may be made, such, for example, as suitable for use with other types of busway, and I, therefore, intend by the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A busway plug device comprising:

(a) a generally rectangular enclosure having top, bottom, and side walls;

(b) a plurality of plug-in type electrical connectors supported on said bottom wall and projecting externally therefrom;

(c) electrical control apparatus within said enclosure and connected electrically in series with said electrical connectors;

(d) said electrical control apparatus comprising switch means for manually opening and closing an electrical circuit connected thereto and means for automatically opening said circuit upon the occurrence of predetermined current therethrough, said automatic opening means comprising heat-genenating currentresponsive means; and

(e) means mounting said electrical control apparatus on at least one of said walls of said enclosure other than said bottom wall, whereby heat generated by said apparatus is transmitted to said one of said walls within said enclosure and dissipated by said one of said walls externally of said enclosure.

2. A busway plug device comprising:

(a) a generally rectangular enclosure having top, bottom, and side walls; 1

(b) a plurality of plug-in type electrical connectors supported on said bottom wall and projecting externally therefrom;

(c) electrical control apparatus within said enclosure and connected electrically in series with said electrical connectors;

(d) said electrical control apparatus comprising a switch for manually opening and closing an electrical circuit connected thereto and fuse-receiving means for supporting a fuse for automatically opening said circuit upon the occurrence of predetermined current therethrough; and

(e) means mounting said electrical control apparatus on at least one of said walls of said enclosure other than said bottom wall, whereby heat generated by said apparatus is transmitted to said one of said walls within said enclosure and dissipated by said one of said walls externally of said enclosure.

3. A busway plug device comprising:

(a) a generally rectangular enclosure having top, bottom, and side walls;

(b) a plurality of plug-in type electrical connectors supported on said bottom wall and projecting externally therefrom;

(c) electrical control apparatus within said enclosure and connected electrically in series with said electrical connectors;

(d) said electrical control apparatus comprising a switch for manually opening and closing an electrical circuit connected thereto and fuse-receiving means for supporting a fuse for automatically opening said circuit upon the occurrence of predetermined current therethrough; and

(e) means mounting said switch on one of said walls of said enclosure other than said bottom wall, and means supporting said fuse-receiving means closely adjacent another wall which is at right angles thereto, whereby heat generated by said switch is transmitted and dissipated by said one of said walls externally of said enclosure.

4. A busway plug device comprising:

(a) a generally rectangular enclosure having top, bottom, and side walls;

(b) a plurality of plug-in type electrical connectors supported on said bottom wall and projecting externally therefrom;

(c) electrical control apparatus within said enclosure and connected electrically in series with said electrical connectors;

(d) said electrical control apparatus comprising a switch for manually opening and closing an electrical circuit connected thereto and fuse-receiving means for supporting a fuse for automatically opening said circuit upon the occurrence of predetermined current therethrough;

(e) means mounting said switch on one of said walls of said enclosure other than said bottom wall where- 7 by" heat generated-bysaid-switch is transmitted to said one of said walls within said enclosure and dis- 7 s'i iated by said one of said walls externally of said enclosure; and

f f) means supporting said fuse-receiving means for supporting, a'fuse closely adjacent said top-wall which is closed by an operable cover.

'5.- A busway plug device comprising:

(:a) a generally rectangular enclosure having top; botv tom, and side walls;

(15) a plurality of plug-in type electrical Connectors supported on said bottoni wall and projecting externia-lly therefrom;

(-c) electrical control p aratus within said enclosure and connected electrically in series with said electrical connectors;

d; said electrical control apparatus comprising a three-phase switch for manuallyopening and closing an electrical circuit connected thereto and fusere'ceivingmeans for sup orting a fuse for automatically opening said circuit upon the occurrence of predetermined current thereth'rough;

" (e) means r'nou r'it'ing' said switch on one of said walls (b) a plurality of: plug in type electrical connectors supported on said bottom wall and projectingexternally therefrom; I

(0) electrical controf apparatus within said enclosure and connected electrically in series with said elec= t-rical connectors;

('d) said electrical control apparatus comprising a switch for manually opening and-closing an electrical circuit connected thereto and fuse-receiving means for supporting a fuse for automatically openingsaid circuit upon the occurrence of predetermined current therethrough;

(e) means mounting said switch on one of said walls of said enclosure other than said bottom wall, and

means supporting said fuse-receiving means closely adjacent another wall which is" at right anglesthereto, whereby heat generated by said switch is trans mitted tosaid one of said walls within said enclosure and dissipated by said one of said walls externally'of said-enclosure; aridv (f) atleast one heatdissipating strap means mounted to said fuse-receiving means and being in juxtaposed relation to said one of said wallswhereby heat gen"- erated' in said fuse is transmitted thereto and there'- through to said" oiie of said walls within said enclosure and dissipatedby said one of said walls eXternal'ly of said enclosure.

References Cited UNITED STATES PATENTS 1,402,123 1/1922 Wadsworth 200-414 3,028,460 4/1962 run-on 311-100 XR 3,200,296 8/1965 Bruestle 317-100 35 ROBERT KL SCHA-EFER, Primary Examiner.

M. GINSBURG, Assistant Examiner. 

1. A BUSWAY PLUG DEVICE COMPRISING: (A) A GENERALLY RECTANGULAR ENCLOSURE HAVING TOP, BOTTOM, AND SIDE WALLS; (B) A PLURALITY OF PLUG-IN TYPE ELECTRICAL CONNECTORS SUPPORTED ON SAID BOTTOM WALL AND PROJECTING EXTERNALLY THEREFROM; (C) ELECTRICAL CONTROL APPARATUS WITHIN SAID ENCLOSURE AND CONNECTED ELECTRICALLY IN SERIES WITH SAID ELECTRICAL CONNECTORS; (D) SAID ELECTRICAL CONTROL APPARATUS COMPRISING SWITCH MEANS FOR MANUALLY OPENING AND CLOSING AN ELECTRICAL CIRCUIT CONNECTED THERETO AND MEANS FOR AUTOMATICALLY OPENING SAID CIRCUIT UPON THE OCCURRENCE OF PREDETERMINED CURRENT THERETHROUGH, SAID AUTOMATIC OPENING MEANS COMPRISING HEAT-GENERATING CURRENTRESPONSIVE MEANS; AND 